Patch "spi: atmel: fixed spin_lock usage inside atmel_spi_remove" has been added to the 3.18-stable tree

Patch "spi: atmel: fixed spin_lock usage inside atmel_spi_remove" has been added to the 3.18-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    spi: atmel: fixed spin_lock usage inside atmel_spi_remove

to the 3.18-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     spi-atmel-fixed-spin_lock-usage-inside-atmel_spi_remove.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Feb 28 16:16:23 CET 2018
From: Radu Pirea <radu.pirea@microchip.com>
Date: Fri, 15 Dec 2017 17:40:17 +0200
Subject: spi: atmel: fixed spin_lock usage inside atmel_spi_remove

From: Radu Pirea <radu.pirea@microchip.com>


[ Upstream commit 66e900a3d225575c8b48b59ae1fe74bb6e5a65cc ]

The only part of atmel_spi_remove which needs to be atomic is hardware
reset.

atmel_spi_stop_dma calls dma_terminate_all and this needs interrupts
enabled.
atmel_spi_release_dma calls dma_release_channel and dma_release_channel
locks a mutex inside of spin_lock.

So the call of these functions can't be inside a spin_lock.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Radu Pirea <radu.pirea@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/spi/spi-atmel.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1416,12 +1416,12 @@ static int atmel_spi_remove(struct platf
 	struct atmel_spi	*as = spi_master_get_devdata(master);
 
 	/* reset the hardware and block queue progress */
-	spin_lock_irq(&as->lock);
 	if (as->use_dma) {
 		atmel_spi_stop_dma(as);
 		atmel_spi_release_dma(as);
 	}
 
+	spin_lock_irq(&as->lock);
 	spi_writel(as, CR, SPI_BIT(SWRST));
 	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
 	spi_readl(as, SR);


Patches currently in stable-queue which might be from radu.pirea@microchip.com are

queue-3.18/spi-atmel-fixed-spin_lock-usage-inside-atmel_spi_remove.patch